working on arcs

src/common/QskArcMetrics.cpp

@@ -25,13 +25,6 @@ static inline qreal qskInterpolated( qreal from, qreal to, qreal ratio )
     return from + ( to - from ) * ratio;
 }
 
-static inline qreal qskAbsoluted( qreal length, qreal percentage )
-{
-    // 100% means -> 0.5 of length
-    percentage = qBound( 0.0, percentage, 100.0 );
-    return percentage / 100.0 * 0.5 * length;
-}
-
 void QskArcMetrics::setThickness( qreal thickness ) noexcept
 {
     m_thickness = thickness;
@@ -93,32 +86,33 @@ QVariant QskArcMetrics::interpolate(
     return QVariant::fromValue( from.interpolated( to, progress ) );
 }
 
-QskArcMetrics QskArcMetrics::toAbsolute( const QSizeF& size ) const noexcept
+QskArcMetrics QskArcMetrics::toAbsolute( qreal radiusX, qreal radiusY ) const noexcept
 {
-    if ( size.width() < 0.0 )
-        return toAbsolute( size.height() );
+    if ( radiusX < 0.0 )
+        return toAbsolute( radiusY );
 
-    if ( size.height() < 0.0 )
-        return toAbsolute( size.width() );
+    if ( radiusY < 0.0 )
+        return toAbsolute( radiusX );
 
-    return toAbsolute( qMin( size.width(), size.height() ) );
+    return toAbsolute( qMin( radiusX, radiusY ) );
 }
 
-QskArcMetrics QskArcMetrics::toAbsolute( qreal size ) const noexcept
+QskArcMetrics QskArcMetrics::toAbsolute( qreal radius ) const noexcept
 {
     if ( m_sizeMode != Qt::RelativeSize )
         return *this;
 
-    QskArcMetrics absoluted = *this;
+    QskArcMetrics m = *this;
 
-    if ( size <= 0.0 )
-        absoluted.m_thickness = 0.0;
-    else
-        absoluted.m_thickness = qskAbsoluted( size, absoluted.m_thickness );
+    if ( radius < 0.0 )
+        radius = 0.0;
 
-    absoluted.m_sizeMode = Qt::AbsoluteSize;
+    const auto ratio = qBound( 0.0, m.m_thickness, 100.0 ) / 100.0;
 
-    return absoluted;
+    m.m_thickness = radius * ratio;
+    m.m_sizeMode = Qt::AbsoluteSize;
+
+    return m;
 }
 
 QskHashValue QskArcMetrics::hash( QskHashValue seed ) const noexcept

src/common/QskArcMetrics.h

@@ -56,8 +56,8 @@ class QSK_EXPORT QskArcMetrics
     QskArcMetrics interpolated( const QskArcMetrics&,
         qreal value ) const noexcept;
 
-    QskArcMetrics toAbsolute( const QSizeF& ) const noexcept;
-    QskArcMetrics toAbsolute( qreal ) const noexcept;
+    QskArcMetrics toAbsolute( qreal radiusX, qreal radiusY ) const noexcept;
+    QskArcMetrics toAbsolute( qreal radius ) const noexcept;
 
     QskHashValue hash( QskHashValue seed = 0 ) const noexcept;
 

src/controls/QskSkinlet.cpp

@@ -210,7 +210,10 @@ static inline QSGNode* qskUpdateArcNode(
     if ( rect.isEmpty() )
         return nullptr;
 
-    const auto absoluteMetrics = metrics.toAbsolute( rect.size() );
+    const auto rx = 0.5 * rect.width();
+    const auto ry = 0.5 * rect.height();
+
+    const auto absoluteMetrics = metrics.toAbsolute( rx, ry );
 
     if ( !qskIsArcVisible( absoluteMetrics, fillGradient ) )
         return nullptr;

src/nodes/QskArcNode.cpp

@@ -11,31 +11,29 @@
 
 #include <qpainterpath.h>
 
-static inline QskGradient effectiveGradient( const QRectF& rect,
-    const QskArcMetrics& metrics, const QskGradient& gradient )
+#define LINEAR_GRADIENT_HACK 1
+
+#if LINEAR_GRADIENT_HACK
+
+static inline QskGradient buildGradient( QskGradient::Type type,
+    const QRectF& rect, const QskArcMetrics& metrics,
+    const QskGradientStops& stops )
 {
-    if ( gradient.isMonochrome() )
-        return gradient;
-
-    bool isRadial = false;
-
-    if ( gradient.type() == QskGradient::Linear )
-    {
-        /*
-            Horizontal is interpreted as conic ( in direction of the arc ),
-            while Vertical means radial ( inner to outer border )
-         */
-        isRadial = gradient.linearDirection().isVertical();
-    }
-
-    auto g = gradient;
-    g.setStretchMode( QskGradient::NoStretch );
-
     const auto center = rect.center();
 
-    if( isRadial )
+    QskGradient gradient;
+    gradient.setStretchMode( QskGradient::NoStretch );
+
+    if ( type == QskGradient::Conic )
     {
-        g.setRadialDirection( center.x(), center.y(),
+        gradient.setConicDirection(
+            center.x(), center.y(), metrics.startAngle() );
+
+        gradient.setStops( stops );
+    }
+    else
+    {
+        gradient.setRadialDirection( center.x(), center.y(),
             rect.width(), rect.height() );
 
         {
@@ -47,24 +45,58 @@ static inline QskGradient effectiveGradient( const QRectF& rect,
             const auto radius = 0.5 * qMin( rect.width(), rect.height() );
             const auto t = metrics.thickness() / radius;
 
-            QskGradientStops stops;
-            stops.reserve( gradient.stops().size() );
+            QskGradientStops scaledStops;
+            scaledStops.reserve( stops.size() );
 
-            for ( const auto& stop : gradient.stops() )
+            for ( const auto& stop : stops )
             {
                 const auto pos = 0.5 - t * ( 0.75 - stop.position() );
-                stops += QskGradientStop( pos, stop.color() );
+                scaledStops += QskGradientStop( pos, stop.color() );
             }
 
-            g.setStops( stops );
+            gradient.setStops( scaledStops );
         }
     }
-    else
+
+    return gradient;
+}
+
+#endif
+
+static inline QskGradient effectiveGradient( const QRectF& rect,
+    const QskArcMetrics& metrics, const QskGradient& gradient )
+{
+    if ( !gradient.isMonochrome() )
     {
-        g.setConicDirection( center.x(), center.y(), metrics.startAngle() );
+        if ( gradient.type() == QskGradient::Stops )
+        {
+            const QskConicDirection dir(
+                rect.center(), metrics.startAngle() );
+#if 0
+            dir.setSpanAngle( metrics.spanAngle() ); // what is "expected" ??
+#endif
+
+            QskGradient g( gradient.stops() );
+            g.setStretchMode( QskGradient::NoStretch );
+            g.setConicDirection( dir );
+
+            return g;
+        }
+
+#if LINEAR_GRADIENT_HACK
+        if ( gradient.type() == QskGradient::Linear )
+        {
+            // to keep the iotdashboard working: to be removed
+
+            const auto type = gradient.linearDirection().isHorizontal()
+                ? QskGradient::Conic : QskGradient::Radial;
+
+            return buildGradient( type, rect, metrics, gradient.stops() );
+        }
+#endif
     }
 
-    return g;
+    return gradient;
 }
 
 QskArcNode::QskArcNode()
@@ -78,22 +110,8 @@ QskArcNode::~QskArcNode()
 void QskArcNode::setArcData( const QRectF& rect,
     const QskArcMetrics& metrics, const QskGradient& gradient )
 {
-#if 1
-    /*
-        Translating linear gradients into conic or radial gradients.
-        This code is a leftover from situations, where only linear
-        gradients had been available. Once the iotdashboard example
-        has been adjusted we will remove this code TODO ...
-     */
-    const auto g = effectiveGradient( rect, metrics, gradient );
-#endif
-
-    /*
-        For the moment using a QPainterPath/QskShapeNode.
-        But we can do better by creatig vertex lists manually
-        like what is done by the box renderer. TODO ...
-     */
-
     const auto path = QskArcRenderer::arcPath( rect, metrics );
-    updateNode( path, QTransform(), rect, g );
+
+    updateNode( path, QTransform(), rect,
+        effectiveGradient( rect, metrics, gradient ) );
 }

src/nodes/QskArcNode.h

@@ -11,6 +11,11 @@
 class QskArcMetrics;
 class QskGradient;
 
+/*
+    For the moment a QPainterPath/QskShapeNode.
+    But we can do better by creatig vertex lists manually
+    like what is done by the box renderer. TODO ...
+ */
 class QSK_EXPORT QskArcNode : public QskShapeNode
 {
   public:

src/nodes/QskArcRenderer.cpp

@@ -9,10 +9,13 @@
 #include <qpainterpath.h>
 #include <qrect.h>
 
-QPainterPath QskArcRenderer::arcPath(
+static inline QPainterPath qskArcPath(
     const QRectF& rect, const QskArcMetrics& metrics )
 {
-    const auto m = metrics.toAbsolute( rect.size() );
+    const auto rx = 0.5 * rect.width();
+    const auto ry = 0.5 * rect.height();
+
+    const auto m = metrics.toAbsolute( rx, ry );
 
     const qreal t2 = 0.5 * m.thickness();
     const auto r = rect.adjusted( t2, t2, -t2, -t2 );
@@ -27,3 +30,59 @@ QPainterPath QskArcRenderer::arcPath(
 
     return stroker.createStroke( path );
 }
+
+static inline QRectF qskArcRect(
+    const QRectF& rect, const QskArcMetrics& metrics )
+{
+    return qskArcPath( rect, metrics ).controlPointRect();
+}
+
+QPainterPath QskArcRenderer::arcPath(
+    qreal radius, const QskArcMetrics& metrics )
+{
+    const QRectF r( 0.0, 0.0, 2 * radius, 2 * radius );
+    return qskArcPath( r, metrics );
+}
+
+QPainterPath QskArcRenderer::arcPath(
+    const QSizeF& diameters, const QskArcMetrics& metrics )
+{
+    const QRectF r( 0.0, 0.0, diameters.width(), diameters.height() );
+    return qskArcPath( r, metrics );
+}
+
+QPainterPath QskArcRenderer::arcPath(
+    const QRectF& rect, const QskArcMetrics& metrics )
+{
+    return qskArcPath( rect, metrics );
+}
+
+QRectF QskArcRenderer::arcRect( qreal radius, const QskArcMetrics& metrics )
+{
+    const qreal d = 2.0 * radius;
+    return qskArcRect( QRectF( 0.0, 0.0, d, d ), metrics );
+}
+
+QRectF QskArcRenderer::arcRect( const QSizeF& diameters, const QskArcMetrics& metrics )
+{
+    const QRectF r( 0.0, 0.0, diameters.width(), diameters.height() );
+    return qskArcRect( r, metrics );
+}
+
+QRectF QskArcRenderer::arcRect( const QRectF& rect, const QskArcMetrics& metrics )
+{
+    return qskArcRect( rect, metrics );
+}
+
+QSizeF QskArcRenderer::arcSize(
+    const QSizeF& diameters, const QskArcMetrics& metrics )
+{
+    if ( qFuzzyIsNull( metrics.spanAngle() ) )
+        return QSizeF();
+
+    if ( qAbs( metrics.spanAngle() ) >= 360.0 )
+        return diameters;
+
+    const QRectF r( 0.0, 0.0, diameters.width(), diameters.height() );
+    return qskArcRect( r, metrics ).size();
+}

src/nodes/QskArcRenderer.h

@@ -12,10 +12,22 @@ class QskArcMetrics;
 
 class QPainterPath;
 class QRectF;
+class QSizeF;
 
 namespace QskArcRenderer
 {
+    // radius
+    QSK_EXPORT QPainterPath arcPath( qreal radius, const QskArcMetrics& );
+    QSK_EXPORT QRectF arcRect( qreal radius, const QskArcMetrics& );
+
+    // diameter
+    QSK_EXPORT QPainterPath arcPath( const QSizeF&, const QskArcMetrics& );
+    QSK_EXPORT QSizeF arcSize( const QSizeF&, const QskArcMetrics& );
+    QSK_EXPORT QRectF arcRect( const QSizeF&, const QskArcMetrics& );
+
+    // bounding rectangle
     QSK_EXPORT QPainterPath arcPath( const QRectF&, const QskArcMetrics& );
+    QSK_EXPORT QRectF arcRect( const QRectF&, const QskArcMetrics& );
 };
 
 #endif